The marble cathedral of Chile: Are these the world's most beautiful caves?
Welcome to the Marble Cathedral - a natural wonder that could be the world's most beautiful cave network.
An azure temple created by nature, the walls of this network of water-filled marble caverns show just how magnificent the precious geography of our planet can be.
Visitors to the water-sculpted blue caverns see light reflected off the turquoise waters of South America's second largest freshwater lake, General Carrera in Patagonia, Chile.
Azure temple: Lake General Carrera in Patagonia, Chile, could be the world's most beautiful cave network
Ancient: The caves have been formed by flowing water over thousands of years
Light bounces into the caverns and strikes the carved marble walls, creating this enchanting lightshow.
The incredible set of pictures has been captured by landscape photographer and environmentalist, Linde Waidehofer, 67, from Colorado, USA.
'It is the water that formed the unique shapes of the marble walls,' explained Ms Waidehofer in her book on the caverns, Blue Light.
'Originally great ice-fields blocked the western end of the lake - today its glacier-fed waters drain into the Pacific Ocean.
'Geologists have a simple explanation for the breath-taking blue of this giant lake.
'They talk of finely ground glacial silt which makes the water an unearthly blue and crystal clear.
'These waters are magic.'
Photographer's dream: Photography students have travelled the world to learn about light in what could be the world's most astonishing classroom
To reach this remote place located in the far southern tip of Chile visitors must fly from the capital, Santiago, 800 miles to the next nearest large city, Coyhaique, and then drive on challenging dirt roads 200 miles south to the lake.
Yet photography students have travelled the world to learn from Ms Waidehofer about light in what could be the world's most astonishing classroom.
Beautiful: But the unspoilt majesty of Lake Carrera is under threat from development